Camera with changeable focal length

ABSTRACT

A focal length changeable camera has a taking lens system which is changed between at least two different focal lengths, namely, a relatively long focal length suitable for a telephotographic mode and a relatively short focal length suitable for a wide-angle photographic mode, and is equipped with a focal length changing mechanism comprising a rotatable changing member driven by a motor, a lever displacing member provided on the rotatable changing member, a motor switching lever engageable with the lever displacing member for switching a motor switch, and a focal length changing member for changing the focal length of the taking lens upon rotation of the rotatable changing member.

This is a division of application Ser. No. 291,450 filed 12/27/88.

BACKGROUND OF THE INVENTION

The present invention relates to a camera with a changeable focallength, and more particularly to a focal length changeable cameraequipped with a motor drive mechanism by which a taking lens system ischanged in focal length.

Recent compact cameras are equipped with taking lens systems of the typein which the focal length can be changed between various focal lengths,for example between a relatively short focal length of approximately 35mm suitable for wide-angle photography and a relatively long focallength of approximately 70 mm suitable for telephotography. Such focallength changeable cameras have taking lens systems which generallyinclude an axially movable master lens and an extra lens which isdisplaced from or moved into the optical path of the taking lens systemupon changing the taking lens system to the relatively long focallength.

In one instance of such a focal length changeable camera disclosed in,for example, Japanese Unexam. Patent Publ. No. 60-114,836 there isprovided a toggle spring to thrust back and forth the axially movablemaster lens in the direction of the optical path or to extend it fromand retract it into the camera body so as to change the focal length ofthe taking lens. The provision of such a toggle spring makes focallength changeable cameras simple in structure but needs relatively largeforce to thrust back and forth the master lens for the change of focallength.

In another instance, as is disclosed in Japanese Unexam. Patent Publs.Nos. 60-163,010 and 61-35,435, a motor for advancing or transporting afilm in the camera is commonly used to thrust back and forth the axiallymovable master lens. The motor is operationally coupled to a movablelens barrel holding the master lens through a one-way clutch comprising,for example, a planetary gearset. Therefore, such motor driven focallength changeable cameras need not only a reverse switch for reversingthe motor in rotation but also a self-housing switch for maintaining themotor reversed. In order to control the operation of these switches, itis necessary to provide a mechanism including, for example, cams andlevers which will generally make the internal mechanisms of the cameracomplicated.

Otherwise, the one-way clutch coupling the lens barrel to the motor ismaintained coupled by a self-holding member which is brought intooperation through an axially movable member in cooperation with theaxial movement of the lens barrel. In this instance, the lens barrelwill receive undesirable external force exerted thereon at angles to theoptical axis of the taking lens system. Such undesirable external forcecauses the optical axis of the taking lens system to deflect or incline.Therefore, it is necessary to provide means such as rollers for theprevention of such deflection or inclination of the optical axis of thetaking lens system.

It is also necessary to provide position sensors such as a limit switchin association with the master lens or its lens barrel in order todetect whether the master lens or the lens barrel is at one of twopossible lens positions, or at a position between the possible lenspositions, thereby stopping the motor. The provision of such positionsensors will also make the internal mechanism of the camera complicated.

Furthermore, it is necessary to provide electrical or mechanicalinterlock means for preventing a shutter release button or a focallength change member from being operated during the time the focallength change member is being operated to change the focal length of thetaking lens system or during the time the shutter release button isbeing operated, respectively. An electrical interlock means isnecessary, which cooperates with a position sensor or sensors such as alimit switch in association with the master lens or its lens barrel inorder to detect whether the master lens or the lens barrel is at one oftwo possible lens positions, or at a position between the possible lenspositions, thereby stopping the motor. The provision of such positionsensors will also make the internal mechanism of the camera complicated.

OBJECTS OF THE INVENTION

It is, therefore, an object of the present invention to provide a focallength changeable camera which can mechanically hold a motor switchturned on to change focal length.

It is another object of the present invention to provide a focal lengthchangeable camera which has a simple structure for controlling a motorfor changing focal length.

It is still another object of the present invention to provide a focallength changeable camera which is provided with a simple mechanicalinterlock structure for interlocking alternately shutter release andfocal length change.

SUMMARY OF THE PRESENT INVENTION

According to a preferred embodiment of the present invention, a focallength changeable camera comprises rotatable changing means driven by amotor; a lever displacing means formed on the rotatable changing means;motor switch control means in the form of a lever cooperating with thelever displacing means; and focal length changing means movable incooperation with rotation of the rotatable changing means for changing ataking lens system between at least two focal lengths, namely, arelatively long focal length suitable for telephotography and arelatively short focal length suitable for wide-angle photography.

When operating an externally operable slider for changing a taking lenssystem between telephotographic and wide-angle photographic modes, themotor switch control lever is rotationally displaced to turn on themotor, rotating the rotatable changing means, thereby changing the focallength of the taking lens system through focal length changing means. Atthis time, the lever displacing means maintains the motor switch leverto hold the motor turned on. The provision of the lever displacing meansand the motor switch lever engageable with each other makes it possibleto hold the motor switch turned on during the change of focal length.

According to another preferred embodiment of the present invention, afocal length changeable camera with a taking lens system which is drivenby a motor to change focal length between at least two different focallengths comprises a motor switch for turning on and off the motor, amotor switch actuating member for causing the motor switch to turn onand off the motor, a motor control cam member driven by the motor andhaving activating peripheral cam sections for displacing the motorswitch actuating member to cause the motor switch to turn on anddeactivating peripheral cam sections for displacing the motor switchactuating member to cause the motor switch to turn off, a memberprovided on the motor control cam member, a focal length changing membercoacting with this member for changing the taking lens system in focallength, and an externally operable focal length changing member fordisplacing the motor switch actuating member from a position wherein themotor switch actuating member is out of contact with the activating camsection to a position wherein the motor switch actuating member is incontact with the activating cam section.

In this embodiment, an externally operable slider is operated to changefocal length. In cooperation with the operation of the external slider,the motor switch actuating member causes the motor switch to turn on,starting the motor to rotate followed by rotation of the motor controlcam member. Upon rotation of the motor control cam member, the switchactuating member is displaced from a deactivating cam section of themotor control cam member to an activating cam section of the motorcontrol cam section, thereby holding the motor switch turned on duringthe focal length change of the taking lens system.

According to still another preferred embodiment of the presentinvention, a focal length changeable camera is provided with aninterlock mechanism. The interlock mechanism desirably comprises shutterrelease means operated to unlock a shutter actuating member for causinga shutter to operate, focal length changing means for changing thetaking lens system between at least the two different focal lengths, aninterlock member movable between a first position disabling the focallength changing means from operating and a second position causing thefocal length changing means to operate, first restraining means in theinterlock member for restraining the interlock member from moving to thesecond position when the shutter release means is operated, and secondrestraining means in the interlock member for restraining the shutterrelease means from being operated when the interlock member is at thesecond position.

In this embodiment, when a shutter release button is operated ordepressed, the shutter release means is displaced to a release positionso as to actuate the shutter actuating member, driving a shutter to makean exposure. On the other hand, when a photographic mode shift slider isoperated, the interlock member is moved from the first to the secondposition, causing the focal length changing means to operate, therebychanging the taking lens system from the telephotographic mode to thewide-angle photographic mode.

If the photographic mode shift slider is operated while the shutterrelease button is depressed, the first restraining means prevents theinterlock member from operating, thereby interlocking the focal lengthchanging means. On the other hand, if the shutter release button isdepressed during the change of focal length of the taking lens system,the second restraining means prevents the shutter release means fromoperating, thereby interlocking the shutter actuating means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a focal length changing camera accordingto the present invention;

FIG. 2 is an exploded perspective illustration showing an essential partof a focal length changing camera of FIG. 1;

FIG. 3 is a sectional view showing the focal length changeable camera ofFIG. 2 in which a taking lens system is in a telephotographic mode;

FIG. 4 is a sectional view showing the focal length changeable camera ofFIG. 2 in which a taking lens system is in a wide-angle photographicmode;

FIG. 5 a partially exploded perspective view showing a mode shiftmechanism of the focal length changeable camera of FIG. 2;

FIG. 6 is a plan view showing the mode shift mechanism of the focallength changeable camera of FIG. 5;

FIGS. 7 through 11 are plan views showing the mode shift operation ofthe mode shift mechanism of the focal length changeable camera of FIG.5;

FIG. 12 is a plan view showing the positions of first and second changelevers when the camera is in the wide-angle photographic mode;

FIG. 13 is a plan view showing the positions of the same said first andsecond change levers when the camera is in the telephotographic mode;

FIG. 14 is a plan view showing an alternative means for displacing amotor switch lever;

FIG. 15 is a plan view showing another alternative means for displacinga motor switch lever;

FIG. 16 is a plan view, partially in block diagram, showing a mode shiftmechanism of the focal length changeable camera according to anotherembodiment of the present invention when the camera is in a wide-anglephotographic mode;

FIG. 17 is a view similar to FIG. 16 but with the parts in a differentposition;

FIG. 18 view similar to FIG. 16 but when the camera is in atelephotographic mode;

FIG. 19 is an exploded perspective view showing an interlock mechanismaccording to the present invention;

FIG. 20 is a front view showing the interlock mechanism of FIG. 19;

FIG. 21 is a front view similar to FIG. 20 but after a release buttonhas been operated; and

FIG. 22 is a front view similar to FIG. 20 in which a mode shiftmechanism is operated.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there are shown various necessary elementsforming essential parts of a camera changeable in focal length, forexample, between two different focal lengths, namely a relatively shortfocal length suitable for wide-angle photography and a relatively longfocal length suitable for telephotography, according to the presentinvention. It is to be understood that camera elements not specificallyshown may take various forms known to those skilled in the art.

As shown, the camera has a lens housing 41 provided on a front wall 40thereof. Inside of the lens housing 41 there is a lens cover comprisingtwo barrier blades 43 and 44 to open and close an opening 45 of the lenshousing 41. The barrier blades 43 and 44 are mechanically operationallyconnected to an externally operable lens cover opening slider 42 to openand close. The camera body is further provided on the front wall 40 witha T-W mode shift slider 46 for shifting the camera into a wide-anglephotographic mode or into a telephotographic mode, a viewfinder window48, light projecting and light receiving windows 49a and 49b of anautomatic focusing device and an electronic flash assembly 50, and onits top wall a shutter release button 51.

As is shown in FIG. 2, a taking lens system includes a master lens 3 anda conversion lens 6. The master lens 3 is supported by a lens holder 4which is mounted in a slidable lens barrel 1 and is moved back and forthby the movable lens barrel 1 along the optical axis L of the taking lenssystem in cooperation with a well-known automatic focusing device (notshown) so as to focus the taking lens system. On one side of the movablelens barrel there is a plate la extending laterally therefrom formedwith a slot 1c, to which plate 1a a bearing sleeve 1b is secured. Thebearing sleeve 1b receives a guide rod 2 extending parallel to theoptical axis L of the taking lens system for guiding the back and forthmovement of the movable lens barrel 1 between a telephotographicposition and a wide-angle photographic position. The guide rod 2supports thereon a coil spring to force the movable lens barrel 1 towardthe telephotographic position.

The conversion lens 6 is inserted into and removed from the optical axisL of the taking lens system by means of a conversion lens shiftmechanism 7 in cooperation with the back and forth movement of themovable lens barrel 1. This conversion lens shift mechanism 7 comprisesa lens holder 7a holding the conversion lens 6, a driven gear 7b securedto the lens holder 7a and a drive gear 7d in mesh with the driven gear7b. The lens holder 7a is forced by a spring 7e to turn toward aposition wherein the conversion lens 6 is coaxial with the optical axisL of the taking lens system.

Behind the conversion lens 6 there is a shutter 8 comprising two shutterblades 8a, and 8b pivotally mounted on a shaft 8c. Each shutter blade8a, 8b is formed with a curved slot that receives a pin 8d driven by ashutter driving mechanism (which is well known in structure andoperation and need not be disclosed in detail herein). Upon up and downmovement of the pin 8d, the shutter blades 8a and 8b are swung inopposite directions to open and close. Behind and close to the movablelens barrel 1 there is a diaphragm 62 as shown in FIGS. 3 and 4.

In order to shift the taking lens system between the telephotographicmode and the wide-angle photographic mode by cooperatively moving themaster lens 3 and the conversion lens 6, there is a focal length changemechanism 10 (which is hereinafter referred to as a T-W mode shiftmechanism). As is shown in FIG. 5, the T-W mode shift mode mechanism 10includes a first change lever 12 which swings to move back and forth themaster lens 3 along the optical axis L and the conversion lens 6 intoand out of the optical axis L. As is shown in FIG. 2, in order to causethe conjoint movement of the master and conversion lenses 3 and 6, thefirst change lever 12 is in contact with a cam surface of a secondchange lever 13 at its one end and is coupled to the plate 1a through apin-and-slot 12d-1c engagement. The cam surface of the second changelever 13 comprises two cam sections: a non-displacing cam section 13awhich causes no displacement of a slide lever 9 disposed between thesecond change lever 13 and a swing lever 7c secured to the drive gear7d, and a displacing cam section 13b which causes the displacement ofthe slide lever 9. When the movable lens barrel 1 moves back and forth,the axial movement of the first change lever 12 swings the second changelever 13 while the first change lever 12 is in contact with thedisplacing cam section of the second change lever 13, so that the slidelever 9 is displaced to swing the swing lever 7c, turning the drive gear7d thereby to insert and remove the lens holder 7a holding theconversion lens 6 from the optical axis L or causes no motion of thesecond change lever 13, or no swinging of the second change lever 13while the first change lever 12 is in contact with the non-displacingsection of the cam surface of the second change lever 13, so that theslide lever 9 is not displaced.

Referring now to FIGS. 3 and 4, the camera is shown in thetelephotographic mode and the wide-angle photographic mode,respectively. As shown, inside the lens housing 41 there is an innerhousing 55 which slidably supports the movable lens barrel 1. Disposedbetween the lens housing 41 and the inner housing 55 are the lensbarrier blades 43 and 44 shown in FIG. 1 which are allowed to open andclose if the camera is in the wide-angle photographic mode shown in FIG.4.

The shutter blades 8a and 8b of the shutter 8 are attached to a shutterbase plate 56 and open and close an opening 56a formed in the shutterbase plate 56. The shutter base plate 56 is formed with four holes 56bfor receiving bosses 55b of the inner housing 55 and is secured to thecamera body 58 with screws 57. The inner housing 55 is secured to thecamera body 58 with screws 59.

Behind the inner housing 55 a retainer plate 60 is attached to theflange of the inner housing 55 and supports the guide rod 2. A bracket61 is attached to the inside of housing 55 and holds the lens shiftmechanism 7.

The operation of the T-W mode shift mechanism 10 will be described indetail with reference to FIGS. 5 through 13. The T-W mode shift slider46, which coacts with a T-W mode set slider 11 through e.g. a lever (notshown), can be operated to move the T-W mode set slider 11 in adirection shown by an arrow in FIG. 5. The T-W mode shift mechanism 10includes the above-noted first and second change levers 12 and 13, ashift control cam 14 acting on the first change lever 12, a motor 15 forrotating the shift control cam 14, a motor switch 16 for actuating themotor 15, a switch lever 17 for keeping the motor switch 16 actuated,and a latch-set lever 18 for swinging the switch lever 17 to turn on themotor switch 16.

The motor 15, as was previously described, is common to T-W mode shiftoperation and to film winding and rewinding and is disposed in a spool15a on which the film is wound up. Rotation of the motor 15 istransmitted to the switching gear arrangement 20 acting as a clutchthrough a reduction gear train G1. The switching gear arrangement 20includes a planetary gear set which comprises a sun gear 20a in meshwith the reduction gear train G1, a carrier 20b mounted coaxially withthe sun gear 20a, a planet gear 20c supported for rotation by thecarrier 20b and in mesh with the sun gear 20a, a first follower gear 20dwith which the planet gear 20c is brought into mesh when the sun gear20a turns in the counterclockwise direction as viewed in FIG. 5 to turnthe carrier 20b, and a second follower gear 20e with which the planetgear 20c is brought into mesh when the sun gear 20a turns in theclockwise direction as viewed in FIG. 5 to turn the carrier 20b.

The carrier 20b of the switching gear arrangement 20 is formed with adetent projection 20f engageable with a projection 27b of the T-W modeset slider 27. When the T-W mode set slider 27 is not operated at itsinitial position, the projection 27b of the T-W mode set slider 27 is inengagement with the detent projection 20f of the carrier 20b, therebyforcing the carrier 20b to move the planet gear 20c into mesh with thefirst follower gear 20d. On the other hand, when the T-W mode set slider27 is operated to move in the opposite direction to that shown by thearrow in FIG. 5, the sun gear 20a turns clockwise to turn planet gear20c and to disengage the projection 27a of the T-W mode set slider 27from the detent projection 20f of the carrier 20b, thereby forcing thecarrier 20b to move the planet gear 20c into mesh with the secondfollower gear 20d.

Rotation of the first follower gear 20d is not only directly transmittedto a gear 67 attached to the film wind spool 15a through a gear train G2but also transmitted to a film rewind gear 68 through a one-way clutchGW in a gear train branched off the gear trains G2. The film rewindinggear 68 has a fork 69 to be coupled to a spool of a patrone containing aroll of film 65 loaded in the camera.

The shift control cam 14 is pivotally mounted on the base plate (notshown) and consists of a toothed section 14a coupled to the secondfollower gear 20e through a connecting gear train 21, a circular camsection 14b and an off-set pin 14c attached to the back surface of theshift control cam 14. The circular cam section 14b is formed with twoperipheral notches 14d at irregular spacings to provide first and secondcam surfaces 14e and 14f therebetween as shown in detail in FIGS. 12 and13. Each notch 14d receives a hook 17a of the switch lever 17. Theoff-set pin 14c, as will be described in detail later, coacts with thelimiting lever 23, the latch-set lever 18 and the first change lever 12to turn them.

The first change lever 12 is supported for swinging movement by a pivotshaft 12c secured to the base plate and is provided with a detent 12afor restricting forward displacement of the movable lens barrel forchanging the camera to the telephotographic mode, and first and secondengaging edges 12b and 12e engageable with the off-set pin 14c of theshift control cam 14. The first change lever 12 is urged by the coilspring 5 to turn in a direction to shift the taking lens system into thetelephotographic mode. The detent 12a is provided with a pivot shaft 23bwhich pivotally mounts the limiting lever 23 with a projection 23aengageable with the detent 12a. The limiting lever 23 acts to limit theswinging movement of the first change lever 12 for shifting the takinglens system into the telephotographic mode and is urged to turn in theclockwise direction by a coil spring 23c as shown in FIG. 5. The end 23dof the limiting lever 23 is disposed in the path of the off-set pin 14cof the shift control cam 14 and is pushed by pin 14c to swing in thecounterclockwise direction through a certain angle upon the rotation ofthe shift control cam 14. Thus, when the shift control cam 14 turns, theoff-set pin 14c causes the limiting lever 23 to swing counterclockwise,thereby disengaging the projection 23a of the limiting lever 23 from thedetent 12a of the first change lever 12. The first change lever 12 isaccordingly allowed to swing in the direction to shift the taking lenssystem into the telephotographic mode.

The first engaging edge 12b is shaped in the form of a quarter of acircle defined by the path of the off-set pin 14c and is brought intocontact with the off-set pin 14c when the first change lever 12 is swungin the counterclockwise direction to shift the taking lens into thetelephotographic mode. During the time the off-set pin 14c can bebrought into contact with the first engaging edge 12b of the limitinglever 12, the shift control cam 14 maintains the first change lever 12unchanged in position through a first one-fourth rotation thereof andturns the same in the counterclockwise direction after the firstone-fourth rotation thereof. The second engaging edge 12e, which isformed as a continuation of the first engaging edge 12b and projectslaterally a little more than the first engaging edge 12b, is broughtinto contact with the off-set pin 14c upon the first change lever 12turning in the clockwise direction to shift the taking lens into thewide-photographic mode.

As is shown in detail in FIGS. 12 and 13, the non-displacing cam section13a of the second change lever 13 is circularly arcuate and lies on partof a circular path of the end 12f of the first change lever 12 and has alength approximately equal to three-fourths of the whole possible strokeof the first change lever 12 necessary to shift the taking lens systembetween the telephotographic and wide-angle photographic modes. Thedisplacing cam section 13b, which has a cam surface positioned insidethe extended arc of the non-displacing cam section 13a, has a triangularrecess to receive therein the end 12f of the first change lever 12. Theend 12f of the first change lever 12 is consequently brought intocontact with the non-displacing cam section 13a when the first changelever 12 travels three-fourths of its possible stroke. At this time, thefirst change lever 12 turns alone leaving the second change lever 13 asit is. After the three-fourths travel of the first change lever 12, theend 12f of the first change lever 12 is brought into contact with thedisplacing cam section 13b, leaving the non-displacing cam section 13a,causing clockwise rotational displacement of the second change lever 13corresponding to the rotational displacement of the first change lever12. As a result, the movable lens barrel 1 moves three-fourths of itspossible movement in the axial direction, thereby inserting theconversion lens 6 into the optical axis L of the taking lens system.

The switch lever 17 is provided with a hook 17a which is received in thenotch 14d of the shift control cam 14 to prevent the shift control cam14 from rotating, and switching finger 17b for turning off the motorswitch 15 upon the hook 17a of the switch lever 17 falling into or beingreceived in the notch 14d of the shift control cam 14. The switch lever17 is pivotally mounted on a shaft 17c for pivotal movement between anoff position wherein the hook 17a of the switch lever 17 is in the notch17a to turn on the motor switch 16 and to prevent the rotation of theshift control cam 14 and an on position wherein the hook 17a of theswitch lever 17 is out of the notch 17a to turn off the motor switch 16and to allow the rotation of the shift control cam 14. Latch-set lever18 is engaged with the off-set pin 14c to push the switch lever 17 tothe off position and, on the other hand, to turn the switch lever 17 tothe on position when operated. To this end, the latch-set lever 18 isprovided with a hooked portion 18a for being latched with a latch lever25 which actually turns the switch lever 17 between the on and offpositions, and first and second engaging surfaces 18b and 18c forturning the latch-set lever 18 in the clockwise direction afterreleasing the latch lever 25 from the hooked portion 18a, therebylatching again the hooked portion 18a with the latching lever 25. Thefirst and second engaging surfaces 18b and 18c are engageable withoff-set pin 14c when the taking lens system is shifted intotelephotographic mode from the wide-angle photographic mode and to thewide-angle photographic mode from telephotographic mode, respectively.

Latch-set lever 18 disposed under the switch lever 17 is mounted forrotation on the base plate by means of the shaft 17c of the switch lever17 and is urged or biased in the counterclockwise direction by means ofa coil spring 29. Between the switch lever 17 and latch-set lever 18there is a torsion spring 24 to urge the switch lever 17 toward the offposition. The latch lever 25 is urged or biased in the counterclockwisedirection by means of a coil spring 25a.

The operating power from the T-W mode shift slider 46 is transmitted tothe switch lever 17 by transmitting the movement of the T-W mode setslider 11 in the direction shown by the arrow in FIG. 5 through atransmission lever 26, a set slider 27 to which the transmission lever26 is attached, the latch lever 25 and the latch-set lever 18.

The transmission lever 26 has a detent 26a engageable with a projection11a of the T-W mode set slider 11 and is mounted for rotation on the setslider 27 by means of a pivot shaft 26b. The transmission lever 26 isfurther urged or biased in the clockwise direction by means of a coilspring 26c (see FIG. 5). A releasing pin 30 is mounted on the base plateto swing the transmission lever 26 so as to release the detent 26a fromengagement with the projection 11a of the T-W mode set slider 11 whenthe transmission lever 26 is in engagement with the projection 11a ofthe T-W mode set slider 11 and moves to the extremity of its movement.

The set slider 27 is mounted on the base plate by means of apin-and-slot engagement for sliding movement in the direction of slidingmovement of the T-W mode set slider 11. The T-W mode set slider 11 andthe set slider 27 are both urged or biased in a downward direction asviewed in FIG. 5 by means of coil springs 28 and 29, respectively.

Operation of the focal length changeable camera thus structured will behereinafter described with reference to the accompanying drawings. Intaking a picture with use of the camera as shown in FIG. 1, the lenscover opening slider 42 is moved to open the barrier blades 43 and 44.In cooperation with the opening of the barrier blades 43 and 44, a powerswitch (not shown) of the camera is turned on to apply electric power toa control circuitry for the motor 15, the shutter 8, an automaticrangefinding device, an electronic flash, etc.

When the barrier blades 43 and 44 are open, the camera is in thewide-angle photographic mode as shown in FIG. 4 and the movable lensbarrel 1 is retracted in a moving area of the lens holder 7a. In thiswide-angle photographic mode, when the release button 51 is depressed,the automatic rangefinding device is actuated to shift the lens holderalong the optical axis L, thereby focusing the master lens 3 on asubject in the field. Thereafter, the shutter 8 is actuated to exposethe film 65, and then the motor 15 is actuated to rotate. Rotation ofthe motor 15 is transmitted to the switching gear arrangement 20 throughthe reduction gear train G1. Since the switching gear arrangement 20places the planet gear 20c in mesh with the first follower gear 20d,rotation of the motor 15 is transmitted to the spool gear 67 through thefirst follower gear 20d and the gear train G2. As a result, the filmwind spool 15 is rotated to wind up the exposed part of the film 65 andto withdraw the film 65 from the film patrone 70 to place an unexposedpart of the film 65 at the exposure position. The shutter 8 isself-cocked with the film wind-up.

To shift the camera from the wide-angle photographic mode as shown inFIG. 4 to the telephotographic mode as shown in FIG. 3, the T-W modeshift slider 46 is operated. In cooperation with the operation of theT-W mode shift slider 46, the T-W mode set slider 11 is moved upwardlyand displaced from a position shown in FIG. 6 to a position shown inFIG. 7. The set slider 27 is consequently moved in the same directionthrough the transmission lever 26 in engagement with the projection 11aof the T-W mode set slider 22. Accordingly a projection 27c of the setslider 27 faces the cutaway 17d of the switch lever 17 to allowcounterclockwise rotation of the switch lever 17.

Through the projection 27a of the set slider 27, the latch lever 25 isturned in the clockwise direction to release the engagement between thelatch lever 25 and the latch-set lever 18, thereby causing the latch-setlever 18 to turn in the counterclockwise direction so as to turn switchlever 17 in the counterclockwise direction through the torsion spring 24stretched between the levers 18 and 25. The hook 17a of the switch lever17 leaves the notch 14d of the shift control cam 14 to turn on the motorswitch 16, actuating the motor 15. When the plate gear 20c moves aroundthe sung ear 20a and is brought into mesh with the second follower gear20e. Through the intermediate gear train 21, rotation of the motor 15 istransmitted to the shift control cam 14 to turn it in the clockwisedirection.

FIG. 7 shows the T-W mode set slider 11 at the extremity of itsmovement. There, the transmission lever 26 abuts against the releasingpin 30 projecting from the base plate, having been turned in thecounterclockwise direction to release or disengage the detent 26a fromthe projection 11a of the T-W mode set lever 22. Thus, the T-W mode setlever 11 is in a position to return but is prevented from returningfully to its initial position because the projection 27c is engaged withthe cutaway 17d of the switch lever 17, which has been turned to the onposition. Accordingly, since the projection 27b of the set slider 27 isout of engagement with the detent projection 20f of the carrier 20b ofthe switching gear arrangement 20, the planet gear 20c is maintained inmesh with the second follower gear 20e. Although the set slider 27 doesnot completely return to its initial position, the engagement betweenthe transmission lever 26 and the projection 11a of the T-W mode setslider 11 is interrupted, thereby to disconnect the set slider 27 fromthe T-W mode set slider 11, and accordingly the taking lens system isnot periodically shifted between the tele- and wide-angle photographicmodes even when the T-W mode shift slider 46 is operated and left in theoperated position.

When the shift control cam 14 begins to turn in the clockwise direction,the limiting lever 23 turns in the counterclockwise direction under theinfluence of the off-set pin 14c as shown in FIG. 8. As a result, thedetent 12a of the first change lever 12 is released from the projection23a of the limiting lever 23 so as to cause the first change lever 12 toturn in the counterclockwise direction about the shaft 12c with thefirst engaging edge 12b following the off-set pin 14c. However, due tothe quartered configuration of the first engaging edge 12b, the firstchange lever 12 does not return to the telephotographic position untilthe shift control cam 14 turns one-fourth of its one revolution.

During the first one-fourth revolution of the shift control cam 14, theoff-set pin 14c comes into contact with the latch-set lever 18,thereafter turning the latch-set lever 18 in the clockwise directionuntil it is latched by the latch lever 25 so as to return the latch-setlever 18 to its initial position. Owing to the return of the latch-setlever 18, the spring 24 is biased or charged to urge the switch lever 17in the clockwise direction. However, at this time, the hook 17a of theswitch lever 17 is in engagement with the first cam surface 14e of thecircular cam section 14b of the shift control cam 14, and so the switchlever 17 cannot turn in the clockwise direction. As a result, the motorswitch 16 is maintained turned on for self-holding during the conversionof the camera into the telephotographic mode from the wide-anglephotographic mode.

The first change lever 12, as shown in FIG. 9, turns, by means of thecoil spring 5, in the counterclockwise direction following the circularmovement of the off-set pin 14c caused by angular displacement of theshift control cam 14 more than approximately one-fourth revolutionthereof. The movable lens barrel 1 is consequently thrust forward toplace the master lens 3 in a position suitable for telephotography. Foraccurately positioning the movable lens barrel 1 in the telephotographicposition, the movable lens barrel 1 is formed with a rear flange 1aabutable against the front wall of the inner housing 55. Upon theabutment of the movable lens barrel 1 against the inner housing 55, thefirst change lever 12 is prevented from turning further.

As was previously noted, since the end 12f of the first change lever 12is in contact with the cam surface of the second change lever 13 urgedor biased by means of the coil spring 7c, the second change lever 13turns with the turning of the first change lever 12. However, as shownin FIG. 12, the second change lever 13 does not follow the turning ofthe first change lever 12; while the first change lever 12 turns throughthree-fourths of one revolution because the end 12f of the first changelever 1 is in engagement with the non-displacing cam section 13a of thesecond change lever 13. In the remaining one-fourth revolution of thefirst change lever 12, the top end 12f of the first change lever 12faces the displacing cam section 13b of the second change lever 13 andso the second change lever 13 is enabled to turn rapidly about the shaft13c. Thereafter, the conversion lens shift mechanism 7 acts followingthe rapid turn of the second change lever 13 to insert the conversionlens 6 into the optical axis L of the taking lens system. This action iseffected through the slide lever 9. Because the conversion lens 6 israpidly inserted into the optical axis L when the master lens 3 issufficiently far away from the conversion lens 6, the conversion lens 6is prevented from striking the master lens 3.

As is shown in FIG. 10, when the shift control cam 14 turns more than ahalf revolution, the hook 17a of the switch lever 17 falls into one ofthe notches 14d of the shift control cam 14 to return the switch leverto its initial position, thereby turning off the motor switch 16 to stopthe motor 15 and releasing the engagement between the projection 27c ofthe set slider 27 and the notch 17d of the switch lever 17 so as toreturn the set slider 27 to its initial position shown in FIG. 6. Thus,the shift gear arrangement 20 has the projection 20f of the carrier 20bpushed with the projection 27b of the set slider 27 to turn the carrier20b in the counterclockwise direction. The planet gear 20c isaccordingly forced to mesh with the first follower gear 20d.

In a manner as described above, the camera is shifted into thetelephotographic mode wherein the movable lens barrel 1 is thrust out ofthe inner housing 55 and the conversion lens 6 is in alignment with theoptical axis L as shown in FIG. 3 from the wide-angle photographic modeas shown in FIG. 4. This mode shift operation is effected particularlyby making use of the first cam surface 14e of the shift control cam 14.As was previously noted, the first cam surface 14e is longer than thesecond cam surface 14f. By making use of the difference in length ofthese first and second cam surfaces 14e and 14f, the limiting lever 23and the latch-set lever 18 are swung or turned in sequence. Thissequential swinging movement makes the motor 15 receive decreasedreactive force from the shift control cam 14.

The camera can be shifted into the wide-angle photographic mode from thetelephotographic mode in substantially the same manner as describedabove. When operating the T-W mode shift slider 46, the switch lever 17is moved out of the notch 14a of the shift control cam 14 to turn on themotor switch 16 as shown in FIG. 11. Simultaneously with this, the T-Wmode set slider 11 is disengaged and disconnected from the transmissionlever 26 by means of the releasing pin 30, so that no repetitiveshifting operation between the telephotographic and the wide-anglephotographic mode is induced even when the T-W mode shift slider 46 isleft in the operated position.

Rotation of the motor 15 is transmitted to the shift cam through thegear train G1 and the switching gear arrangement 20. At the beginning ofrotation of the shift control cam 14, the off-set pin 14c pushes thesecond engaging surface 18c of the latch-set lever 18 to return it toits initial position as well as to engage it with the latch lever 25.During further rotation of the shift control cam 14, the off-set pin 14cabuts against the second engaging edge 12e to turn the first changelever 12 in the clockwise direction against the coil spring 5, therebymoving the movable lens barrel 1 backward. Simultaneously with this, thefirst change lever 12 cooperatively turns the second change lever 13 inthe counterclockwise direction thereby to remove the conversion lens 6from the optical axis L through the slide lever 9 and the conversionlens shift mechanism 7 as shown in FIG. 2.

During continuous rotation of the shift control cam 14, the off-set pin14c forces the first change lever 12 to further rotate in the clockwisedirection. At the extremity of clockwise movement of the first changelever 12, the detent 12a of the first change lever 12 rides over theprojection 23a of the limiting lever 23 and then engages it as is shownin FIG. 12. Thus, the first change lever 12 is locked with the limitinglever 23 at the telephotographic position and, thereby, prevented fromturning further in the counterclockwise direction. The shift control cam14 can rotate a little more after the lockage of the first change lever12 to allow the off-set pin 14c to move away from the second engagingedge 12e of the first change lever 12, finally being returned to andplaced at a position shown in FIG. 6.

If in fact the shift control cam 14 and the first change lever 12 returnto their initial position as shown in FIG. 5, the hook 17a of switchlever 17 falls into the notch 14d of the cam section of the shiftcontrol cam 14 to turn off the motor switch 16 and allows the set slider20 to return to its initial position. Thus, the planet gear 20c isbrought out of mesh with the second follower gear 20e and into mesh withthe first follower gear 20d. This mode shift is effected by making useof the second cam surface 14f of the shift control cam 14. Since theoff-set pin 14c of the shift control cam 14 and the first change lever12 are brought into contact with each other on the side remote from thepivot shaft 12c of the first change lever 12 when the master lens 3 isshifted from the telephotographic position to the wide-anglephotographic position, the first change lever 12 turns with relativelyhigh torque. The first change lever 1 can accordingly be moved with easeagainst the coil spring 5 which forces the movable lens barrel 1 to moveforwardly.

At the completion of exposure of all the exposable frames of the film65, the motor is automatically reversed in rotation in a manner wellknown to those skilled in the art to rotate the rewinding gear 68, andhence the hook 69, so as to rewind continuously the exposed film on thespool 15a in the film patrone 70.

It is to be noted that rotation of the shift control cam 14 is stoppedthrough the engagement between the cam surfaces of the shift control camhaving different lengths and arranged at unequal spacings and the switchlever as stop means. Because of the different lengths of the camsections arranged at unequal spacings, the shift control cam rotatesintermittently at different intervals. This makes it possible toproperly coordinate the various movable levers with the shift controlcam, particular to the respective cam sections, at different timings.Accordingly, the output power of the motor can be efficiently used.

FIGS. 14 and 15 illustrate alternative embodiments of the shift cam andits associated elements. As shown in FIG. 14, a shift cam 80 is formedwith peripheral projections 81 for controlling a motor switch 82 to turnon and off. In FIG. 15, a shift cam 83 is provided with a closed camgroove 84 for controlling a motor switch 85 to turn on and off. Theprovision of the cam groove 84 enables effecting the turning on and offof the motor switch without the provision of the latch-set lever 18, thelatch lever 25, etc. used in the first embodiment.

According to the above embodiment, by sliding the T-W mode set slider 11in the direction shown by the arrow in FIG. 5, the shift cam 14 can becontrolled in rotation through the switch lever 17 in engagement withthe shift cam 14 and the latch-set lever 18. Furthermore, owing to thecoaction of the switch lever 17 and the latch-set lever 18, the motorswitch 16 can be self-held, which ensures shift operation of the camerabetween the wide-angle and telephotographic modes only upon operation ofthe T-W mode shift slider 46 and avoids the need for provision ofelectric self-holding circuits. Furthermore, because switch lever 17 isadapted to turn on the motor switch 16 after the detent 17a of theswitch lever 17 has completely left the notch 14d of the shift cam 14,the motor 15 is prevented from starting to rotate during controlledrotation of the shift cam 14 and various operable parts and mechanismsare, therefore, free from undesirable force. This improves thedurability of the mechanism.

Referring now to FIGS. 1 to 4 and 16 to 18, which show an alternativeembodiment of the present invention, the first change lever 12 coactswith a lever drive mechanism 70. The lever drive mechanism 70 includes amotor 71, a motor switch 72 for starting and stopping the motor 71, aswitch activating lever 73 for turning on and off the motor switch 72, amotor control cam 75 which is rotated by the motor 71 and has motordeactuating cam surfaces 75a and motor actuating cam surfaces 20barranged alternately on the periphery thereof for controlling the switchactivating lever 73, and a pin 76 off-set on the back surface of themotor control cam 75. The first change lever 12 directly coacts with theoff-set pin 76 to change or shift the taking lens system between thetele- and wide-angle photographic modes. The T-W mode shift slider 46 isoperationally linked to the switch activating lever 73 so as to displaceit to turn on the motor switch 72. The switch activating lever 73 isurged or biased by a coil spring 74 to turn in the counterclockwisedirection as viewed in FIG. 16. A driver circuit 77 is provided tocontrol the motor 71 according to a control signal from the motor switch72.

A limiting lever 78, coacting with the first change lever 12, is turnedin the counterclockwise direction with the off-set pin 76 to allow thefirst change lever 12 to turn when the motor control cam 75 turns and atother times limits the turning of the first change lever 12. In the sameway as described in connection with the previously described embodiment,the first change lever is restrained from turning when moving to shiftthe taking lens system from the wide-angle photography mode to thetelephotographic mode as a result of, for example, the abutment offlange la of the movable lens barrel 1 against the inner housing 55.

The focal length changeable camera thus constructed operates as follows:

When taking a picture using the camera shown in FIG. 1, the lens coveropening slider 42 is moved to open the barrier blades 43 and 44. Incooperation with the opening of the barrier blades 43 and 44, a powerswitch (not shown) of the camera is turned on to apply electric power tothe control circuitry for the motor 71, the shutter 8, an automaticrangefinding device, an electronic flash, etc.

With the barrier blades 43 and 44 open, the camera is in the wide-anglephotographic mode shown in FIG. 4 and the movable lens barrel 1 isretracted into the area of movement of the lens holder 7a. In thiswide-angle photographic mode, when the release button 51 is displacedthe automatic rangefinding device is actuated to shift the lens holder 4along the optical axis L, thereby focusing the master lens 3 on asubject in the field. Thereafter, the shutter 8 is actuated to exposethe film (not shown) and then the motor 71 or a film winding motor (notshown) separate from the motor 71 is actuated to wind up the exposedfilm in a similar manner as described in connection with the previousembodiment, simultaneously with the self-cocking of the shutter 8.

To shift the camera from the wide-angle photographic mode as shown inFIG. 4 to the telephotographic mode as shown in FIG. 3, the T-W modeshift slider 46 is operated. In cooperation with the operation of theT-W mode shift slider 46, the switch activating lever 73 is turned inthe counterclockwise direction to turn on the motor switch 72, startingthe motor 71 to rotate. The detent end 73a of the switch activatinglever 73 consequently leaves the motor deactuating cam surface 75a ofthe motor control cam 75, allowing the motor control cam 75 to rotate.Then, the detent end 73a of the switch activating lever 73 is broughtinto and maintained in contact with the motor actuating cam surface 75bof the motor control cam 75. The motor switch 72 is thus maintainedturned on. Hence, the motor control cam 75 can rotate continuously evenwhen the T-W mode shift slider 46 is released or returned to its restposition. During the rotation of the motor control cam 75, the off-setpin 76 forces or pushes the limiting lever 78 to turn in thecounterclockwise direction as viewed in FIG. 16, allowing the firstchange lever 12 to turn in the clockwise direction by means of the coilspring 5. Through the pin-slot (12d-1c) engagement, the movable lensbarrel 1 is thrust forward. In cooperation with this, the end 12f of thefirst change lever 12 is adjacent the displacing cam section 13b of thesecond change lever 13, and thus the second change lever 13 is able toturn rapidly in the clockwise direction about the shaft 13c to shift theslide lever 9. The conversion lens shift mechanism 7 accordingly actsfollowing the rapid turning of the second change lever 13 to insert theconversion lens 6 into the optical axis L of the taking lens system.Because the conversion lens 6 is rapidly inserted into the optical axisL when the master lens 3 is sufficiently far away from the conversionlens 6, the conversion lens 6 cannot strike or hit the master lens 3.

When the T-W mode shift slider 46 is operated again to displace theswitch lever 73, the motor switch 72 is turned on, actuating the motor71 to rotate so as to turn the motor control cam 75. The first changelever 12 is consequently turned in the clockwise direction by means ofthe off-set pin 76 of the motor control cam 75 to retract the movablelens barrel 1 within the inner housing 55. In cooperation with theretracting movement of the movable lens barrel 1, the conversion lens 6is displaced from the optical axis L. Thus, the camera is shifted fromthe telephotographic mode to the wide-angle photographic mode.

At the completion of exposure of all the exposable frames of the film,the motor is automatically reversed in rotation in a manner well knownto those skilled in the art to rotate the rewinding gear with a hookconnected to a spool of a film patrone so as to rewind continuously theexposed film on the spool in the film patrone.

It is preferred to provide the focal length changeable camera,constructed as above and shown in FIGS. 1 to 4, with means or amechanism for preventing shutter operation and mode shift operation frombeing effected simultaneously. To this end, there is provided aninterlock mechanism for interlocking the shutter release mechanism andthe focal o length changing mechanism, shown in FIGS. 19 through 22. Theinterlock mechanism includes a body release member displaced incooperation with the shutter button 51. The body release membercomprises a primary slidable lever 120 and a secondary slidable lever121. A lock lever 123 is displaceable upon sliding movement of thesecondary lever 120. Lever 123 releasably engages a shutter actuatinglever 124 for causing a shutter driving device 122 well known in the artto effect an exposure. The interlock mechanism further includes a modeshift lever 125 which is slidable upon operation of the T-W mode shiftslider 46, an interlock lever 126 displaceable upon displacement of themode shift lever 125, and a T-W mode set slider 11 for operationallyconnecting or interlocking the interlock lever 126 to the mode shiftmechanism 10.

The primary and secondary slidable levers 120 and 121 are formed withslots 120a and 121a extending in the direction of their movement, theseslots receiving guide pins 120b and 121b by which they are slidablerelative to a base plate (not shown) and being connected with each otherby a coil spring 131. The primary slidable lever 120 is urged or biasedby a coil spring 119 normally to move toward the upper left as viewed inFIG. 19. According to the above lever arrangement, the depression of theshutter button 51 causes the primary slidable lever 120 to movedownwardly followed by the secondary slidable lever 121 connected to theprimary slidable lever 120 through the coil spring 131. When thesecondary slidable lever 121 moves downwardly, a lug or detent 133 ofthe secondary slidable lever 121 abuts a pin 132 mounted on the locklever 123.

The primary slidable lever 120 has a film winding interlock lever 134pivotally mounted thereon by means of the guide pin 120b and coacts witha film rewinding mechanism 135 well known in the art. The film windinginterlock lever 134 can turn in the counterclockwise direction a viewedin FIG. 19 while the film rewinding mechanism 135 is in operation,bringing its end recess 134a into engagement with a lug or detent 126aof the interlock lever 126 so as to be thereby restrained againstmovement. In this way, mode shift of the camera between the tele- andwide-angle photographic modes is prevented during the rewinding of anexposed film.

The secondary slidable lever 121 is formed with a notch 121c in a sideedge thereof. A release lock lever 136 coacts with the lens coveropening slider 42 and is formed with a hook 136a at its end which isbrought into engagement with the recess 121c of the secondary slidablelever 121 when the lens cover opening slider 42 is not operated, tomaintain the barrier blades 43 and 44 closed. The secondary slidablelever 121 accordingly does not coact with the shutter release button 51during the engagement of the release lock lever 136 therewith, therebypreventing the shutter 8 from operating. Since the release lock lever136 is operated to turn in the clockwise direction following theoperation of the lens cover opening slider 42 for opening the barrierblades 43 and 44 and thereby disengaging the hook 136a of the releaselock lever 136 from the notch 121c of the secondary slidable lever 121,the secondary slidable lever 121 can move. The depression of the shutterbutton 51 causes the lock lever 123 to move through the primary andsecondary slidable levers 120 and 121 so as to actuate the shutterdriving device 122.

The mode shift lever 125 is supported for sliding movement in thesliding direction of the secondary slidable lever 121 by the guide pins121b. The mode shift lever 125 is formed with a limiting detent 125a forallowing the clockwise motion of the interlock lever 126 which is causedwhen the T-W mode shift slider 46 is operated.

The interlock lever 126 is biased in the clockwise direction by means ofa spring 126b and is formed with an arm 126c which is brought intoengagement with the limiting detent 125a of the mode shift lever 125 torestrain rotation of the interlock lever 126 and is further providedwith first and second limiting edges 129 and 130. The first limitingedge 129, extending radially, is brought into engagement with aprojection 137 of the secondary slidable lever 121 when the secondaryslidable lever 121 moves downward to restrain clockwise rotation of theinterlock lever 126 during the depression of the shutter release button51 and guides the projection 137 of the secondary slidable lever 121 tomove in a radial direction of the interlock lever 126. The secondlimiting edge 130, extending about a portion of the periphery of lever126, is brought into engagement with a projection 137 of the secondaryslidable lever 121 when the interlock lever 126 rotates in the clockwisedirection in cooperation with the downward movement of the mode shiftlever 125 to restrain downward movement of the secondary slidable lever121 during the mode shift operation of the T-W mode shift slider 46. Thesecond peripheral limiting edge 130 is shaped as part of a circle havingits center at the pivot pin 121b of the interlock lever 126 and extendsfrom the first radial limiting edge 129.

The shutter actuating lever 124 is biased toward the left as viewed inFIG. 19 by means of a spring 138 but slides toward the right following aone-frame advance of the film by a film advancing mechanism 139 totension the spring 138, thereby charging the shutter actuating lever124. The shutter actuating lever 124, when fully charged, is retained bylock lever 123. The shutter actuating lever 124 is provided with a pin124a mounted thereon which triggers an automatic focusing device 122aand then the shutter driving device 122 upon the shutter actuating lever124 being released and moving rapidly.

The operation of the focal length changeable camera thus constructedwill be hereinafter described with reference to FIGS. 1 to 4 and 19 to22. If the barrier blades 43 and 44 are both closed, the release locklever 136 is in a position wherein the hook 136a of the release locklever 136 is in engagement with the notch 121c of the secondary slidablelever 121 and the secondary slidable lever 121 cannot slide downwardeven if the primary slidable lever 120 is moved downward as a result ofthe depression of the shutter release button 51, so that the shutter 8is not actuated.

When taking a picture with the camera, the lens cover opening slider 42is moved to open the barrier blades 43 and 44. In cooperation with theopening of the barrier blades 43 and 44, a power switch (not shown) ofthe camera is turned on to apply electric power to a control circuit. Atthis time, the secondary lever 121 and the release lock lever 136 aredisengaged from each other to ready the camera for actual use.

When the barrier blades 43 and 44 are open, the camera is in thewide-angle photographic mode as shown in FIG. 4 and the movable lensbarrel 1 is retracted into the space in which the lens holder 7a canmove. In this wide-angle photographic mode, the primary and secondaryslidable levers 120 and 121 move downward to push down the lock lever123. As a result, the automatic focusing (AF) device is actuated toshift the lens holder 4 along the optical axis L, thereby focusing themaster lens 3 on a subject in the field. Thereafter, the shutter 8 isactuated to expose the film, and then the film advancing motor isactuated to rotate the film winding spool so as to wind up the film andto withdraw an unexposed part of film from the film patrone in order toplace an unexposed part of the film in the exposure position.

To shift the camera from the wide-angle photographic mode as shown inFIG. 4 to the telephotographic mode as shown in FIG. 3, the T-W modeshift slider 46 is operated. In cooperation with the operation of theT-W mode shift slider 46, the mode shift lever 125 is moved downward.The interlock lever 126 is turned in the clockwise direction by thespring 126b following the motion of the limiting detent 125a of the modeshift lever 125, causing T-W mode set slider 11 to move toward theright. The mode shift mechanism 10 is accordingly actuated to shift thecamera from the wide-angle photographic mode to the telephotographicmode.

If the shutter release button 51 is depressed while the T-W mode shiftslider 46 is operated, the second limiting edge 130 of the interlocklever 126 is engaged with the projection 137, moving the primaryslidable lever 120 downward against the spring 131 but restrainingfurther downward movement of the secondary slidable lever 121. Thisprevents the lock lever 123 from moving downward so as not to allow theshutter driving device 122 to operate. Therefore, the shutter 8 can beprevented from operating even though the shutter release button 51 isdepressed during the operation of the T-W mode shift slider 46.

As is shown in FIG. 22, since secondary slidable lever 121 movesdownward during the depression of the shutter release button 51, theinterlock lever 126 is prevented from rotating in the clockwisedirection through the engagement of the first limiting edge 129 of theinterlock lever 126 with the projection 137 of the secondary slidablelever 121, thereby preventing the interlock lever 126 from following thedownward movement of the mode shift lever 125 caused as a result of theoperation of the T-W mode shift slider 46 during the depression of theshutter release lever 51. The T-W mode set slider 11 cannot move, whichprevents the mode shift of the camera. Thus, the camera can be preventedfrom shifting in mode even when the T-W mode shift slider 46 isoperated, while the shutter release button 51 is depressed.

At the completion of exposure of all the exposable frames of the film,the motor is automatically reversed in rotation in the same manner asdescribed in connection with the previous embodiments to rotate therewinding gear with a hook connected to the spool of the film patrone soas to rewind continuously the exposed film on the spool in the filmpatrone. As is shown in FIG. 20, during this film rewinding, since thefilm winding interlock lever 134 rotates counterclockwise to engage thedetent 126a of the interlock lever 126 with its recess 134a, so asthereby to be prevented from rotating, the mode shift operation isinterlocked during film winding.

Although in this embodiment the body release member consists of adouble-lever structure including the primary and secondary slidablelevers 120 and 121 connected to each other by means of the spring 131and is constructed to allow only the primary slidable lever 120 to movewhen the shutter release button 51 is accidentally depressed while theT-W mode shift slider 46 is operated, the body release member mayinstead consist of a single slidable member.

What is claimed is:
 1. A focal length changeable camera having a takinglens system changeable between at least two different focal lengths,namely, relatively long and relatively short, said cameracomprising:shutter release means operable to unlock a shutter actuatingmember for causing a shutter to operate; focal length changing means forchanging said taking lens system between said at least two differentfocal lengths; an interlock member movable between a first positionpreventing said focal length changing means from operating and a secondposition causing said focal length changing means to operate; firstrestraining means provided on said interlock member for restraining saidinterlock member from moving to said second position when said shutterrelease means is operated; and second restraining means provided on saidinterlock member for restraining said shutter release means from beingoperated when said interlock member is in said second position.
 2. Afocal length changeable camera as defined in claim 1, wherein saidshutter release means includes an externally operable shutter releasemember and a member slidable in a direction in which said externallyoperable shutter release member is operated to unlock said shutteractuating member for causing said shutter to operate.
 3. A focal lengthchangeable camera as defined in claim 2, wherein said interlock memberis a rotatable interlock lever.
 4. A focal length changeable camera asdefined in claim 3, wherein said first restraining means is a rotationrestraining surface for guiding an engaging portion of said rotatableinterlock lever in a diametric direction of said interlock member andwhich engages with said engaging portion of said slidable member torestrain said rotatable lever from rotating to actuate said focal lengthchanging means.
 5. A focal length changeable camera as defined in claim4, wherein said second restraining means is a slide restraining surfacethat extends from said rotation restraining surface for engagement withsaid engaging portion of said slidable member of said shutter releasemeans to restrain sliding movement of said slidable member upon saidrotatable interlock lever moving to said second position.